The present invention relates to trailers for the transport of glass plates.
Glass plates may be transported by semi-trailers, and often by platform semi-trailers. A semi-trailer is a trailer without wheeled axles on its front end, instead having a mechanism, such as a kingpin or gooseneck, for connecting the trailer to a towing vehicle (such as a diesel tractor) that both tows the trailer and supports the trailer front end vertical load. The trailer typically has multiple wheeled axles at its rear end so that groups of two or four wheels rotate about the same axis and so that the trailer has at least two such wheel groups that rotate about at least two parallel axes.
A platform, or flatbed, trailer typically includes a flat loading deck without permanent sides or roof, where the trailer's chassis has a load-carrying main frame that supports the deck from underneath. The deck may sometimes have different levels, including one or more that drop below a main deck level. In glass transport trailers, a frame, often in the cross-sectional shape of an “A,” is secured to the deck and defines planar receiving surfaces on opposite sides of the “A” cross-section that receive one or more sheets of glass to be secured to the A frame. To cover the glass, a tarp may be secured over the A frame or over a rectangular frame secured to the deck about the A frame. Since the A frame and, if present, a rectangular tarp frame or other enclosure, however, are not part of the chassis structure that distributes load from the deck to the wheels and the towing vehicle, these structures add to the trailer load without providing structural support.